function getTheme() {
    var theme =  $.data(document.body, 'theme');
    if (theme == null) {
        theme = 'classic';
    } else {
    	var query = window.location.toString();
    	var oReg=/^(.*?)\?(.*?)$/gi;
    	var arrPara = query.replace(oReg,"$2").split("&");
    	var params = {};
    	for(var i in arrPara){
    		var arrTemp = arrPara[i].split("=");
    	    params[arrTemp[0]] = arrTemp[1];
    	}
    	if (params['theme'] != null) {
    		theme = params['theme'];
    	}
    }
    var url = "/style/style." + theme + '.css';
	
    if (document.createStyleSheet != undefined) {
        document.createStyleSheet(url);
    } else $(document).find('head').append('<link rel="stylesheet" href="' + url + '" media="screen" />');
    
    $.data(document.body, 'theme', theme);
    return theme;
};